Transport of para-aminohippurate and cholic acid by isolated surviving preparations of epithelium from iris and ciliary body of rhesus monkey eyes was demonstrated, and the chemical kinetics of the processes were measured. The kinetics of the uptake of these two substances were affected differently by a series of inhibitors. The results were consistent with the hypothesis that the processes responsible for the accumulation were different for the two substances but shared some common features. The knowledge of how various organic acids are transported in the eye is useful in devising effective schedules for administratton of drugs to the eye.